PCB Cavity Manufacturing via Annular Bump Adhesive Lamination
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Solution Overview
Problem
The existing method for manufacturing printed circuit boards with cavities faces challenges in removing the protective layer covering the pad, which can affect the reliability of the connection between the pad and electronic components if residual protective layer remains.
Innovation Solution
A method involving the formation of annular bumps on substrates and using an adhesive layer with an opening to create a laminated structure, where the bumps prevent adhesive material from contaminating the exposed pad, eliminating the need for additional protective layers and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is applied to cover the pad during manufacturing, then the pad is protected from damage, but the protective layer becomes difficult to remove completely and may remain in the cavity affecting connection reliability
Solution Approach 1:
The patent extracts the protective function from a separate protective layer and relocates it to the adhesive layer itself. The adhesive layer is designed with specific properties (such as selective adhesion or differential curing) that allow it to protect the pad during manufacturing while enabling complete removal or controlled exposure after the cavity is formed, eliminating the need for a separate protective layer and its subsequent removal.
Solution Approach 2:
The adhesive layer is given multiple functions: it bonds the substrates together and simultaneously provides protective coverage for the pad during manufacturing. This multi-functional design eliminates the need for separate protective layers, simplifying the manufacturing process while ensuring complete protection and easy removal without affecting connection reliability.
2Reliability
If additional protective layers are used to ensure complete pad exposure, then connection reliability is improved, but manufacturing complexity and costs increase
Solution Approach 1:
The patent merges the protective function with the adhesive layer, combining two previously separate functions (bonding and protection) into a single material layer. This integration reduces the number of manufacturing steps, eliminates the need for separate protective layer application and removal processes, and simplifies the overall manufacturing process while maintaining connection reliability.
Solution Approach 2:
The adhesive layer is designed to perform multiple functions simultaneously: providing substrate bonding and protecting the pad during manufacturing. This multi-functionality reduces manufacturing complexity by eliminating the need for additional protective layers and their associated application and removal steps, while ensuring reliable electrical connections.
3Strength
If the adhesive layer is applied without openings, then bonding strength is maximized, but adhesive material may contaminate the exposed pad affecting electrical communication
Solution Approach 1:
The adhesive layer is designed with spatially varying properties: in regions requiring bonding, the adhesive provides strong adhesion between substrates, while in regions corresponding to exposed pads, the adhesive layer is configured to either not apply, apply selectively, or be removable. This local differentiation allows the adhesive to provide bonding strength where needed while preventing contamination of the pad, ensuring reliable electrical communication.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures reliable electrical communication by preventing adhesive contamination, reducing manufacturing complexity and costs, and enhancing the connection reliability between the pad and electronic components.
Implementation Method 1
a first adhesive layer which defines an opening therein; laminating the first substrate, the second substrate, and the first adhesive layer together
Data Source
AI summary
A method for manufacturing a printed circuit board with cavity includes following steps. First, a first substrate is provided. The first substrate includes a first electrically conductive layer defining an exposed portion and a laminating portion. Second, a second substrate is provided. The second substrate includes an unwanted portion corresponding to the exposed portion and a preserving portion. Third, a first annular bump surrounding the exposed portion is formed. Fourth, a second annular bump surrounding the unwanted portion is formed. Fifth, a first adhesive layer defining an opening is provided. Sixth, the first and second substrates are laminated to the first adhesive layer, the exposed portion and the unwanted portion are exposed in the opening, and the second annular bump is in contact with the first annular bump. Seventh, the unwanted portion is removed and a cavity is defined, the exposed portion is exposed in the cavity.